For a certain product it was found that annual sales volume could be well described by a third-order autoregressive model. The estimated model obtained was as follows:

xt = 188 + 1.90xt-1 - 0.46xt-2 + 0.16xt-3 + et For 2015, 2016, and 2017, sales were 858, 904, and 966, respectively. Calculate sales forecasts for the years 2018 through 2020.